Delivery devices for administering a therapeutic agent to a patient are available in a variety of configurations. In one such configuration, a delivery device includes an infusion set to deliver therapeutic substances to a patient transcutaneously, e.g., to a target subcutaneous site. Such infusion sets generally include a cannula that provides a transcutaneous pathway through which a therapeutic substance may be administered to a patient. The cannula typically includes an insertion needle for providing an opening in the patient's skin through to place the cannula transcutaneously; thereafter the needle may be removed leaving the cannula transcutaneously positioned. The therapeutic substance desired to be delivered to the patient via the cannula is typically retained in a therapeutic agent source that is connected to the cannula via flexible tubing.
These and other types of infusion sets may be intended to remain in a transcutaneous position, and to deliver a therapeutic substance to a patient, over a period of time. For example, insulin delivery devices are often intended to infuse insulin to a patient for a period of time, e.g., about three days, without removal.
Because infusion sets may be used for multiple days, the risk of infection at the infusion site exists. This risk is of constant concern to users of such infusion sets and healthcare professionals. The risk of infection increases as the time period of use increases, thereby limiting the duration of use of the infusion set and requiring frequent replacements.
Accordingly, as infusion sets for the delivery of therapeutic substances to patients continues to be of importance in health management, there continues to be an interest in devices and methods that decrease the risk of infection associated with infusion sets. Of particular interest are infusion devices for the delivery of therapeutic substances to patients that decrease the risk of infection and increase the period of time an infusion set may be left in place to deliver a therapeutic substance to a patient.